英语高手来一下！___in the dark, his head hit against the wall.

___in the dark, his head hit against the wall.
A.Walking B His walking
CWhen he was walking D While walking
A为啥不对？读起来挺顺口的啊。。
答案是C
觉得D也对额。。。有啥区别？

英语高手来一下 There are too many ___in the sentence. How much did she ___in the supermarket? 英语高手来区别一下` 英语高手来翻译一下 英语高手来一下阿 ~~~英语高手来翻译一下~~~~~~~~ 英语高手来一下！帮个忙！ we catch the enemy general ___in the battle 请英语高手翻译一下sample as the image is